<fb:fbml>
<?php  
// Prepare the invitation text that all invited users will receive.  
$content = <<<FBML  
<fb:name uid="$_SESSION['userid']" firstnameonly="true" shownetwork="false"/> muốn mời bạn thử ứng dụng này!
<fb:req-choice url="{$facebook->get_add_url()}" label="Thử ứng dụng!"/>  
FBML;  
?>  
<fb:request-form action="http://apps.facebook.com/myapp/" method="POST" invite="true" type="Favorite Games" content="<?php echo htmlentities($content);?>">  
    <fb:multi-friend-selector max="20" actiontext="Mời dùng thử ứng dụng!" showborder="true" rows="5"/>
</fb:request-form>  
</fb:fbml>